Handbook for Light Artillery

by A. B. Dyer

Caps.—The regular cap or exploder is employed. It consists of a hollow copper cylinder about ¼ inch in diameter and from one to two inches long, and contains 15 to 20 per cent or more of fulminate of mercury mixed with other ingredients into a cement, which fills the closed end of the cap.

Fuzes.—The double-tape fuze is the best. Single-tape fuze may be used when the ground is only a little wet.

Nippers and Pincers.—For cutting the fuze, and after it is inserted in the cap for squeezing the cap tightly around the fuze.

Funnel.—Used in charging with loose powder.

DRILL-HOLES.

As a general rule drill-holes and charges for dynamite should be comparatively small. In heavy work the holes should be large in size and less in number, and the amount of dynamite should be in proportion to the work done.

Charging with Cartridges.—The charge must fit and fill the bottom of the bore, and be packed solid. Take a cartridge as nearly as possible of the same size as the bore, and cut it into sections of about twice or three times the diameter. With a hard-wood rammer, as large as will run freely in the hole, press these sections into the bore-hole one by one with sufficient force until each section is driven to the bottom and expanded laterally so as to fill the hole solidly in every direction. If the cartridge is smaller than the hole, slit it lengthwise. Metallic rammers must not be used.

Priming.—Cut off squarely the end of the fuze and thrust it into the cap up to the fulminate. If the fuze is too large, scrape it down, and if too small wind it with paper. Then clamp the cap to the fuze with the nippers, being careful not to disturb the fulminate in the cap. If for a wet hole, smear the junction of the fuze and the cap with bar-soap or the like, to make it water-tight. Now open the end of the cartridge, and with a pointed stick make a hole in the explosive and insert the cap (with the fuze attached) the full length of the cap, and press the explosive firmly about the cap. Next gather the cartridge-paper about the fuze and tie it there strongly with a string, so that the cap cannot be withdrawn from the explosive. Cut off so much of the cartridge as is not needed, and the primer is complete. Thus prepared, place it in the drill-hole and press it with a wooden rod into contact with the charge.

Tamping.—This is of great importance. Always tamp if you can, and with the best materials and in the strongest manner. In deep and down holes water is good. A shallow tamp of water amounts to very little. A shallow tamp of sand or clay is better. In driving and packing the tamp next to the primer be careful not to explode the cap; the first handful of tamp should always be pressed down gently. In fissures or artificial cracks surround the charge with mud, clay, sand, or water, if possible.

Explosion of Blast.—In most cases it is better not to cut off the required length of fuze until the hole is tamped. Then cut off at a safe length and fire by igniting with a match or fuzee. If it misses fire, be careful in taking out the tamping not to approach nearer the cap than within two or three inches; then put in another cartridge and fire it. Never pick out the charge. After inserting the primer it is well to put a ball of newspaper or some substance readily recognized on top of it and then the tamping. If then the tamping has to be removed, warning will be given on approaching the primer.